Thursday, 22 December 2005

For the first time anywhere in the world, psychologists at California-based company Omneuron and Stanford University have demonstrated that people can be taught how to reduce their experience of pain with the aid of real-time images of their brain activity.

Healthy participants had a painful stimulus applied to the back of their hand. At the same time they learned to use mental strategies - such as concentrating on another part of their body, or viewing the pain as a neutral experience - to control levels of activity in their anterior cingulate gyrus (a brain area known to be involved in pain perception), displayed to them live using real-time functional magnetic resonance imaging. All the while they provided a continuous rating of how painful the stimulus was.

The researchers found that the pain was perceived as being significantly less intense when the participants reduced the activity in their anterior cingulate gyrus compared with when they increased activity in that region. A similar effect was observed when the experiment was repeated with patients suffering from chronic pain - they were able to reduce their pain by lowering activity in their anterior cingulate.

A number of control conditions supported the researchers' interpretation of the results. The same control over pain wasn't shown when a different set of participants were taught the same mental strategies but without the real-time brain images; nor when participants used real-time brain images to learn to control activity in a part of the brain (the posterior cingulate) not involved in pain perception; nor when participants were given false real-time feedback of activity in their anterior cingulate. "Any effects of expectation or suggestion created by the displays themselves or by the subjects' perception of their control over brain activation were identically matched in these control subjects, who nonetheless did not show an improvement in their control over pain", the researchers said.

Now that this study has demonstrated the feasibility of using real-time brain images to help people learn to control an aspect of their behaviour or mental experience, more work is planned to test the potential benefit of this intervention with other conditions. The study also raises interesting philosophical questions. Did the images of the participants' own brains allow them to master their thoughts, or did their mental strategies allow them to control their brain activity? Which was the means and which was the ends to controlling their pain?
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